1. Field of the Invention
The present invention relates to a document management system that manages documents, method and search apparatus.
2. Description of the Related Art
As an example of conventional technology for searching for versions of a document, Japanese Patent Laid-Open No. H09-34763 discloses a document management system that stores a document in association with the document ID of an immediately previous and an immediately subsequent version of the stored document. Such a document management system enables acquiring a specified version of a certain document by successively tracing through the document IDs of the immediately previous and immediately subsequent versions of the document that are associated with the certain document.
A conventional document management system manages operations such as document creation, editing, and duplication (copy), and each time a version is updated by an operation, a new document is generated and assigned a new document ID by the document management system. However, the document management system cannot detect operation execution events in cases where a document is generated, duplicated, or updated without using the functions of the document management system, such as a case in which a correction or the like is made to a document that has been emailed by a mailer or downloaded to a local environment. Accordingly, the document management system cannot generate, attach, or store a document ID to maintain the association between documents, and therefore cannot maintain the newer-older relationship between the original document and the new document. As a result, a desired version of a document cannot be retrieved.
The above situation would frequently occur in cases such as where a document management system is operating on an intranet in a general office. Examples of such cases include retrieving a document from the document management system and copying the document to a notebook PC or removable medium in order to take the document off the intranet. In such a case, even if the document is placed back into an environment connected to the intranet, the document management system cannot detect the document. In other words, the document cannot be specified by a document ID since the document was not managed in the document management system with use of a document ID. Accordingly, it is not possible to trace back to previous versions or search for related versions.
Also, if a downloaded document is saved in a server shared between departments in order to be disclosed to another department or transmitted to a member of another department by email etc., the document management system cannot detect that the document has been emailed. In other words, the document ceases to be managed in the document management system with use of a document ID and cannot be specified by a document ID, and therefore the emailed document cannot be managed in a newer/older relationship with a document in the document management system. Also, a search for related versions cannot be performed since the document management system does not store location information for transferred documents either.
In other conventional technology, there are cases in which documents having the same filename or document name are assumed to be the same file, and the version relationship between such documents is judged based on the update dates of the documents. In such cases, if a user saves a new version of a document using a different filename or document name, the new version cannot be judged to be a derivation of the original document. Furthermore, there are many cases in which attribute information such as the update date is not retained at a time of transmission or reception by email, thereby making it difficult to judge the version relationship based on attributes. A method for detecting the legitimate version relationship does not exist in such cases, and there is a risk of version relationship information being falsified.